This is a plat fossil concretion from Mazon Creek with a example of the species Neuropteris cf ovata . | |||
Location: | Mazon Creek, Braidwood, Illinois , USA | ||
Size of concretion : | about 78 x 48 mm | ||
Age: | Upper Carboniferous, Pennsylvanian , Carbondale Fm. (about 300 Ma) |